1. Field of the Inventions
The field of the invention relates generally to wheeled carrying or transporting devices and more particularly to telescoping handles used to facilitate convenient conveyance of such devices.
2. Background Information
Recently, wheeled baggage, for example, has been equipped with telescoping handles. A conventional telescoping handle often comprises two telescoping poles, one on either side of the bag, each of which comprises two segments, an inner telescoping segment and an outer segment affixed to the bag itself. The telescoping poles allow the user to extend the handle to a comfortable length while pulling the bag. But the telescoping poles can be collapsed to allow the handle to be retracted whenever it is convenient, e.g., when the bag is stowed.
Locking pins are often used to secure the extended position of the handle to prevent handle from collapsing unexpectedly. Sometimes, the locking pins are spring loaded bearings that require substantial axial force to collapse the telescoping pole. In other cases, the locking pins are mechanically coupled to an actuator on the handle which does not disengage the lock unless the button is depressed. In other instances, a combination of an actuator and spring loaded bearings can be used. In any event, the locking pins must be received by a hole in opposite segment of the telescoping pole. Typically, the segments are hollow tubes with their inner width or diameters decreasing in size so as to allow each successive segment to fit inside one another.
FIG. 1 is a diagram illustrating how a locking mechanism is configured in relationship to two segments a telescoping pole. In the collapsed configuration illustrated on the left, a large portion of internal segment 102 resides within external segment 104. In the extended configuration illustrated on the right, a small portion of internal segment 102 can reside within external segment 104. It can be locked in this configuration with a locking mechanism comprising hole 106 in the external segment and locking pin 108 on the internal segment. The configuration is locked when locking pin 108 engages hole 106. Often, the locking pin 108 is mechanically coupled to a button (not shown) to retract the locking pin 108 when the user wishes to unlock the telescoping pole from the extended configuration.
When extended such that pin 108 is engaged with hole 106, the associated bag can be pulled by the handle. This can, however, introduces stress along the length of the telescoping pole. The heavier the bag and/or rougher the terrain across which the bag is being pulled, the greater the stresses can be. Further, some users have been known to lift a bag by the telescoping handle to overcome an obstacle. Such lifting can relieve all the weight from the wheels and impart the weight into a longitudinal force on the telescoping handle. The brunt of the stresses created along the handle is often imparted directly on the portion of segment 104 that form hole 106. The stresses are often enough to cause hole 106 to deform. In fact, even the act of extending a telescoping handle can cause stresses on hole 106 that can lead to deformation of hole 106.
Eventually, hole 106 can deform to such a degree that pin 108 will no longer engage hole 106 sufficiently. When this occurs, the handle will often collapse unexpectedly rendering the bag somewhat useless, at least for its intended purpose of being able to be wheeled about.
FIG. 2 illustrates the consequence of prolonged or intense longitudinal forces on a hole 106 of a telescoping handle. As can be seen on the right, hole 106 can become enlarged and distorted as a result of excessive or prolonged exposure to longitudinal forces from locking pin 108. Again, the result of the distortion is that the locking pin 108 no longer engages the hole in a secure manner, leading to play in the telescoping handle even when locked. This can lead to instability in navigating the bag, possibly to the point of rendering the telescoping handle inoperable.
One cause for the resulting distortion illustrated in FIG. 2 is the fact that pole segment 104 is often comprised of a light weight weaker material, such as aluminum, as compared to locking mechanism 108, which is often made from a more durable stronger material such as steel or iron.